This proposed conference will be the fourth in an AACR series focused specifically on the science of cancer health disparities. The previous conferences on The Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved were held November 27-30, 2007, February 3-6, 2009, and September 30-October 3, 2010 and attendance has steadily grown each year. Racial and ethnic disparities in cancer rates are well documented. While data suggest that access to quality care contributes to cancer disparities, other factors also play a major role, including tumor biology, genetics, hormonal status, lifestyle and behavior, screening policies, comorbidities, environmental exposure and risk, quality of and response to therapy, and post- therapeutic surveillance. The goal of this conference and the conference series is to bring together scientists and other professionals working in a variety of disciplines to discuss the latest findings in the field and to stimulate the development of new research in cancer health disparities. Transdisciplinary interactions between a variety of disciplines including basic science, clinical research, population science, behavioral research, and cancer survivorship, are needed to move the field forward and make progress in reducing and eliminating disparities as they relate to cancer. PUBLIC HEALTH RELEVANCE: Cancer incidence and death statistics show that certain racial and ethnic groups in the United States suffer disproportionately from cancer and its associated effects. Although some disparities may be explained by socioeconomic factors, there is a biological basis as well. For example, research has identified differences in hormonal status and a number of BRCA1 and BRCA2 variants that are more common among African Americans. Differences in inherited susceptibilities and molecular pathways for pathogenesis have been implicated as a source of prostate cancer disparities. There is a need to bring together scientists, physicians, and other health professionals to foster discussions and collaborations that will move the field forward and make progress in reducing and eliminating cancer health disparities.